Model for illustrating cell division



ea, 18, 11923. mamas P. H. POPE MODEL FOR ILLUSTRATING CELL DIVISION Filed Oct. 2. 1922 INVENTOR ATTORNEY Patented Dec. 18, llg

paras a r ares arias rH ILrr HUNTLEY POPE, or ron'rnann; oaneon.

, MODEL roe ILLUSTRATIN'G CELL DIVISION.

- Application filed October 2,1922. Serial No. 591,688.

.e mah, State of Ore on, have invented certain rounded with thread like structures radi new and useful improvements in Models for Illustrating Cell Division; and I do hereby declare the following to be a full. .clear, and exact description of the invention, suchas will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to transparent models, and more particularly totransparent models designed for the purpose of illustrating cells. The principal object of the invention is to provide a series of cell models showing-the successive stages in the process of cell division. I

It is well known that, as a rule, a single cell is microscopic in-sizeand'consists of several distinct parts. The cell comprises a cell wall containing a, semi-fluid or .jelly like substance or cytoplasm, and'a central T body,'or nucleus. The nucleus is/surrounded by a thin membrane, and contains a jelly like substance slightly different from the cytoplasm. not always, contains a small body, the nucleolus. A fine net work runs through the nucleus and supports a multiplicity of fine granules, or thread like bodies of a substance that stains readily with acid dyes, hence, it is called chromatin. A small body, called a centrosome, lies outside the nucleus.

At the beginning of the division process the centrosome divides in two the two new centrosomes draw apart and become surally disposed with respect. to the centrosomes. Some of these threads extend from one centrosome to the other and form a spindle shaped. 'figure. Meanwhile, the chromatin gathers into a single coiled thread. gradually increasing the size. This thread finally breaks up into a number of rod like bodies called chromosomes (color bodies). The chromosomes then become arranged in a sort of disc or plate transverse to the long axis of the cell, the centrosomes having drawn to the opposite poles of the cell.. At this point a striking change takes place in the cell structure. Each chromosome splits longitudinally into exact halves,

and one-half-ls drawn toward each pole The nucleus usually, th'ough along the spindle fibers or threads. The chromosomes cluster around the centrosomes and then the body of the cell begins to diori inal cell.

his process of cell division occurs in all the cells that make u the bodies of plants and animals. Accor ingly, the subject of cell division must be taught in'all biology I courses. As the subject is ordinarily taught the student is given specimens to view under a microscope, and is provided with charts and drawings illustrating the various stages in division process. In the ordinary method of teaching this subject the student is able to see the illustrations of the cells in two dimensions only, and it has been found that the student oftentimes gets a wrong impression of the true nature of the cells, due to this representation in two dimensions only. Accordingly, one object of the present invention is to provide representations of a cell in different stages of cell division, making them of such size that all of the details can readily be seen and examined from any angle. lhe main purpose of the inventioni is to provide transparent'oell models which may be used to supplement either the microscopic slides inthe laboratory or the in conjunction with the accompanying drawings.

In the drawings:

Fig. l is a perspective view of a model representing a typical cell in the resting condition;

Fig. 2 is a perspective view of a model. representing the prophase of cell division;

Fig. 3 is a perspective View of a; model representing the metaphase of cell division;

.Fig. 4 is a perspective view of a model representing the anaphase of cell division;

Fig. 5 is a perspective view of a model representing a later anaphase of cell d1v1- sion than that shown in Fig. 4:; and

Fig. 6 is a perspective view of a model representing the completion of the process of cell division.

By referring to the drawings and more mil) llild matic box 1 representing the cell wall, and

enclosing the nucleus 2. The cell wall 1 may be made of celluloid, glass, or other suitable transparent material. Celluloid has been found to be superior to glass due to the fact that the celluloid is tough and durable. The shape of a cell is typically spheri cal, but in animal or plant tissues the pressure of contiguous cells usually renders it polyhedral, and in many of the membranes of the body it takes the shape of a prism. The square prismatic shape illustrated in the drawings represents a possible shape of a cell, this particular shape being chosen for its ease of manufacture. and also because models of this configuration may be easily packed for shipping, and will not roll off a table or'desk. It is to be understood that octagonal, hexagonal, spherical and other shapes may be used, it it is so desired.

As shown in the drawings, the nucleus 2 is suspended in the center of the model by means of two members 3. These membets 3 may be made of strips of celluloid, or the nucleus may be suspended by other suitable means.

The nucleus2 comprises a nuclear membrane 4 of transparent material, such as celluloid, or glass; this membrane being spherical in shape. The space within the nuclear membrane is filled with a net work of fibers having ranules of a dark substance supported t ereon. The linin fibers, or net work within the nuclear membrane, may 'be made of slender strips of celluloid cemented together with acetone, or they may be made of spun glass. The granules representing the chromatin ma be made of a thick solution of celluloid in acetone and colored in an -suitable manner. Wax or otherplastic su stances may be used also for the purpose of representing the chromatin. The dark body 5 shown in Fig. 1 represents the nucleolus; This nucleolus 5 may be made of wax and colored blue or any other suitable color. It may be supported within the nubeclear membrane by means of the linin rs. The model shown in Fig. 2 represents the prophase of cell division. From the drawing it is apparent that the model shown in 2 is similar in all respects to that shown in ig 1, except that the chromatin is gathered into a. thick thread 6 coiled within the nucleus and. called the spiremej and the linin fibers and nuclear membrane shown in Fig. .1 have disappeared. The spireme thread 6 may be made of a slender rod of paraflin warmed and 'bent into position, the thread being held in place by a frame work of .strips 7 of celluloid cemented with Metone. r

metaphase and shows the spireme thread broken up into a definite even number of chromatin bodies 8, these bodies having split longitudinally into halves and arranged themselves in a plane transverse to the long axis of the cell. The number of chromosomes 8 shown in the drawings is eight, but this number may be varied indifferent series. The chromosomes 8 are supported in the center of the model b means,

of a transparent plate 9 supporte by the cell wall. This plate 9 may be made of celluloid or other suitable transparent material and may be fastened to the cell wall in any suitable manner. Two centrosomes 10 and 10 are shown disposed near the ends of the cell. These centrosomes are supported by a plurality of fibers 11 connecting them with the chromosomes and representing the spindle fibers which exist in the cell at this stage of cell division. One fiber goes to each chromosome and accessory fibers run par allel to these and interconnect the centrosomes 10 and 10. Short fibers 12 extend out radially from the centrosomes.

The chromosomes 8 may be made of parattached to the plate 9 by any suitable means. For example, if the plate 9 is made of celluloid, the chromosomes may be attached thereto by means of Canada balsam The model shown in Fig. 4 sh ows the anaphase, the chromosomes 8 having begun to migrate toward the poles of the cell, leaving the fibers 11 stretched between them. Two diaphragms or plates 9' are used for the purpose of supporting the chromosomes. The structure of this model is substantially the same as that of the 'model shown in Fig.

somes 10 and 10 to the chromosomes 8 and interconnect the latter. The different parts of the model of Fig. 4 are composed of the same materials as the corresponding parts of the model shown in Fig. 3.

The model shown in Fig. 5 shows a later anaphase than that shown in Fig. 4. In Fig. 5 the chromosomes 8 have drawn together at the two poles, and the centrosomes have disappeared, The fibers 11 extend between the chromosomes forming a spindle .afiin or other plastic material and may be 3. The fibers 11 extend from the centrorepresenting the inner parts of the cell, and a The plate 15 represents the cell wall which the chromatin. has formed across the equator of the origistructures of strings of beads on wires.

within the cel I 3. A model of the type described comprising acell wall consisting of transparent material, and a nucleus comprising a plurepresenting a centrosome and forming a ra lity of plastic bodies.

- 4. A model ofthe type described comprising a cell wall consisting of transparent materials, a nucleus comprising a plurality re'raoee $33 sha ed body. The parts of the model shown of plastic bodies and means for supportin ig. 5 may be made ofthe same materials ing said nucleus within the cell wall.

as the corresponding parts of the other figures. The plate 9 supporting the spindle ing a cell wall consisting of transparent fibers 11 is merely for the purpose of supmaterial, a nucleus comprising a plurality port and does not represent any. part of the of plastic bodies, and a transparent casing cell. enclosing said plastic bodies and represent- Fig. 6 shows a model representing the inqthe nuclear membrane.

completion of the division process, the two new cells being completely formed.- The ing a cell wall consisting of transparent machromosomes are broken u 14 that are scattered througii the two nuclei of thin strips of plastic material represent on linin fibers as in the resting cell shown in ing linin fibers, a plastic body represent- Fig. 1. The nucleoli 5 have reappeared. ing the nucleolus and granules representing 7 A model of the type described comprisnal cell thus dividing the original cell in ing a cell wall consisting of transparent two. I material, .and a nucleus comprising a plu- It is to be understood that the size and rality of thin strips of plastic material proportions of the various parts may'be representing linin'fibers, a colored body varied as desired, or special features may representing the nucleolus, chromatin granbe added. For example, the hereditary ules consisting of celluloid dissolved in characters of some .cells may be shown on acetone,and a transparent casing representthe chromosomes. For instance, the heredi- King the nuclear membrane.

tary characters of Drosophila may be rep- 8. A model of the type described comresented by painting the chromosomes in prising a cell wall and a membrane fixed to rings of dlfilBI'GlTt colors. The beaded apsaid cell wall for supportin bodies reprepearance seen in the chromosomes of some senting the inner parts of t e cell. forms could be represented by making these I 9. A model of the type described comprising a cell wall consisting of transparlit is to be understood that the term ent material, a membrane fixed to said cell plastic materials, applied to the mawall, a plurality of wires supported by said terials of which some of the Various parts membrane and-representing the fibers of the are made, is intended to include all plastic cell.

compositions such aswax, paraflin, elluloid, and glass, glassbeing plastic at igh. tem, peraturesl 10. A model of the type described comprising a cell ,Wall consisting of transparent material, a membrane fixed to said cell ,1 claim: wall, a plurality of wires supported by said 1. A model of the ty cri ed CO membrane and representing the fibers of the prising acell wall consisting of transparent cell, a plurality of. plastic bodies in contact material, and plastic bodies within the cell with said wires and representing chromowall representing the other parts of the cell. somes.

2. A m del of the type descri ed m- 115A model of the type described com p i inge C l Wall Il g of transparent prising a cell wall consisting of transparent material, plastic bodies within said cell wall at rial, a membrane, fixed to said cellwall,

plurality of wires supported by said memmeans for "supporting said plastic bodies brane and representing the fibers of the cell,

wall. a plurality ofplastic bodies in contact with said wires and representing chromosomes, anda plastic body at each end of said cell center from which the fibers radiate.

rnrrrr HUNTLEY Porn.

5. A model of the type described compris- I E: A model of the type describedcompris- I E In testimony whereof I afix my signatnre.

into granules terial, and a nucleus comprising a plurality 

